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Home >> GMC >> 1995 >> Forward Control 7.4 N >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 7.4L >> Trouble Code Charts >> Code 45, Rich Exhaust Indication >> O2 Sensor Contamination
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O2 Sensor Contamination

O2 sensor contamination, caused by silicone in certain fuels or use of improper RTV sealant, may cause a White-powdery coating to cover O2 sensor. The false high signal voltage produced (or low oxygen content sensed) is interpreted by control module as a rich mixture, causing control module to set Code 45.